|Budget Amount *help
¥3,200,000 (Direct Cost : ¥3,200,000)
Fiscal Year 1999 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1998 : ¥2,300,000 (Direct Cost : ¥2,300,000)
The main purpose of the present research was to investigate the punictogen element (X) dependences of physical properties in ternary rare-earth compounds CePtX (X=Sb,As,P,N) and CePdX (X=As,P,N). The another one was to prepare single crystals of EuPdSb and PrPtBi, polycrystals of which show interesting physical properties as reported by us previously.
Firstly, we report crystal structures of these compounds.
It is found that CePtSb has a LiGaGe-type crystal structure, while CePtAs and CePtP have YPtAs type. As for CePdX, CePdAs has a LiGaGe-type, while CePdP has a BeZrSi-type. Unfortunately, we have not yet succeeded in preparing CePtN and CePdN.
Both LiGaGe, YPtAs and BeZrSi have a hexagonal crystal structure and positions of the constituent elements in the unit cell is nearly the same. Therefore, these compounds is a suitable one for systematic investigation of the X dependences of the physical properties.
Next, we report physical properties of these compounds.
Both CePtAs and CePtP show very strong anisotropy of transport properties. We have also detected signals of the dHvA effect. From the analyses of the signal, it is found that the Fermi surface is of two-dimensional cylindrical shape, in agreement with the transport properties. We have also observed dHvA effect of CePdAs.
As for the magnetic properties, it is found that the easy axis of magnetization of CePtX changes from c-axis to c-plane continuously as X changes fm Sb through As to P.
EuPdSb has a TiNiSi-type crystal structure and we have succeeded in preparing single crystal. From the detailed studies of specific heat under the magnetic field and high-field magnetization, we obtained T-H phase diagram of EuPdSb. Furthermore, we observed dHvA effect of EuPdSb. This is the first dHvA signal observed in TiNiSi-type crystal structure.